and running with my existing LLVM 3.2. The build failed again with the same error as in the description. I actually got a warning during the build that this sort configuration has not been tested with my version of LLVM but that it will go ahead and try the build anyway.
So I just downgraded the LLVM to 3.0, ran the make clean & perl boot and now running the make with iOS simulator configuration.

Currently, in the instructions, there is an indication to checkout the latest Cabal/cabal-install (it has the latest required patch).

I built and installed the latest Cabal package and it is listed under ghc-pkg.

Then I ran bootstrap.sh from cabal-install directory but got this error:

Checking installed packages for ghc-7.7.20130831...
Cabal is already installed and the version is ok.
transformers is already installed and the version is ok.
mtl-2.1.2 will be downloaded and installed.
deepseq is already installed and the version is ok.
text-0.11.3.1 will be downloaded and installed.
parsec-3.1.3 will be downloaded and installed.
network-2.4.1.2 will be downloaded and installed.
time is already installed and the version is ok.
HTTP-4000.2.8 will be downloaded and installed.
zlib-0.5.4.1 will be downloaded and installed.
random-1.0.1.1 will be downloaded and installed.
stm-2.4.2 will be downloaded and installed.
Downloading mtl-2.1.2...
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 13723 100 13723 0 0 8526 0 0:00:01 0:00:01 --:--:-- 11165
[1 of 1] Compiling Main ( Setup.hs, Setup.o )
Linking Setup.a ...
<no location info>:
Warning: Couldn't figure out linker information!
Make sure you're using GNU ld, GNU gold or the built in OS X linker, etc.
ld: warning: could not create compact unwind for .LFB3: non-standard register 5 being saved in prolog
ld: warning: PIE disabled. Absolute addressing (perhaps -mdynamic-no-pic) not allowed in code signed PIE, but used in _ZCMain_main_info from Setup.o. To fix this warning, don't compile with -mdynamic-no-pic or link with -Wl,-no_pie
Setup: No cabal file found.
Please create a package description file <pkgname>.cabal
Error during cabal-install bootstrap:
Configuring the mtl package failed

Environment variables I set for bootstrap.sh where:

GHC=i386-apple-darwin11-ghc

GHC_PKG=i386-apple-darwin11-ghc-pkg

Any ideas as to what might be causing this to happen?

[Edited] I can confirm that I can run bootstrap.sh successfully agains the standard build of ghc and ghc-pkg (version tried was 7.6.3).

As a follow up to my comment above, I realised I have the latest cabal-install (from head) already built when I built it agains standard ghc (7.6.3). So I went ahead and I ran the example: i386-apple-darwin11-cabal install network, but still got an error but with quite a bit more detail (ran with -v2 flag).

Ok, so I ignored the issue in my above comment and went straight to the next step, i.e. making sure hsc2hs is new enough, etc.

This worked and I can confirm that I have the example running on the iOS device (simulator).
I compiled the sample Haskell source code (.a file) and added it to the xcode project that I then ran on the device simulator. Got both the system outputs as expected (one from Haskell main and another from main.m).

Regarding the problem in my previous comment, I still hope someone can comment, even if it leads to nothing more than some knowledge gain.